okay, help me with my confusion, what are you doing to start your truck? If you are starting it at the solenoid is there someone holding the clutch pedal down? Or is the engine starting with the clutch pedal up because you have bypassed the clutch switch by going to the starter solenoid?

starting and cranking are two separate things.

when you crank the engine over normally with the key, the clutch has to be pushed in to close the contacts in the clutch switch to allow power to get to the starter solenoid. If you are cranking the starter by jumping the solenoid, how are you doing that? and you supplying power to the little terminal (the "S" terminal) on the solenoid that is supposed to be from the ignition switch?

Every engine requires four basic ingredients to start: sufficient cranking speed, good compression, adequate ignition voltage (with correct timing) and fuel (a relatively rich air/fuel mixture initially). So if your car fails to start, you can assume it lacks one of these four essential ingredients. But which one?

To find you, you need to analyze the situation. If the engine won't crank, you are probably dealing with a starter or battery problem.